package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import com.hmdp.dto.Result;
import com.hmdp.entity.Voucher;
import com.hmdp.entity.VoucherOrder;
import com.hmdp.mapper.VoucherOrderMapper;
import com.hmdp.service.ISeckillVoucherService;
import com.hmdp.service.IVoucherOrderService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.utils.RedisIdWorker;
import com.hmdp.utils.UserHolder;
import lombok.extern.slf4j.Slf4j;
import org.redisson.api.RLock;
import org.redisson.api.RedissonClient;
import org.springframework.aop.framework.AopContext;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.core.io.ClassPathResource;
import org.springframework.data.redis.connection.stream.*;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import javax.annotation.PostConstruct;
import javax.annotation.Resource;
import java.time.Duration;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.concurrent.*;

/**
 * <p>
 * 服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Slf4j
@Service
public class VoucherOrderServiceImpl extends ServiceImpl<VoucherOrderMapper, VoucherOrder> implements IVoucherOrderService {

    @Autowired
    private ISeckillVoucherService seckillVoucherService;
    @Autowired
    RedisIdWorker redisIdWorker;
    @Autowired
    StringRedisTemplate stringRedisTemplate;

    @Resource
    RedissonClient redissonClient;

    public static final DefaultRedisScript<Long> SECKILL_SCRIPT;
    static {
        SECKILL_SCRIPT = new DefaultRedisScript<Long>();
        SECKILL_SCRIPT.setLocation(new ClassPathResource("seckill.lua"));
        SECKILL_SCRIPT.setResultType(Long.class);
    }

    private static final ExecutorService SECKILL_ORDEREXECUTOR = Executors.newSingleThreadExecutor();
    @PostConstruct
    private void init() {
        SECKILL_ORDEREXECUTOR.submit(new VoucherOrderHandler());
    }

    private class VoucherOrderHandler implements Runnable {
        String queueName = "stream.orders";
        public void run() {
            while (true){
                try {
                    //1.获取消息队列中的订单信息 XREADGROUP GROUP g1 c1 COUNT 1 BLOCK 2000 streams.order >
                    List<MapRecord<String, Object, Object>> list = stringRedisTemplate.opsForStream().read(
                            Consumer.from("g1", "c1"),
                            StreamReadOptions.empty().count(1).block(Duration.ofSeconds(2)),
                            StreamOffset.create(queueName, ReadOffset.lastConsumed())
                    );
                    //2.判断消息获取是否成功
                    if(list == null || list.isEmpty()){
                        //如果获取失败，说明没有消息，继续下一次循环
                        continue;
                    }
                    //3.解析消息中的订单信息
                    MapRecord<String, Object, Object> record = list.get(0);
                    Map<Object, Object> value = record.getValue();
                    VoucherOrder voucherOrder = BeanUtil.fillBeanWithMap(value, new VoucherOrder(), true);
                    //4.如果获取成功，可以下单
                    handleVoucherOrder(voucherOrder);
                    //5.ACK确认 SACK stream.orders g1 id
                    stringRedisTemplate.opsForStream().acknowledge(queueName,"g1",record.getId());
                } catch (Exception e) {
                    log.error("处理订单异常", e);
                    handlePendingList();
                }
            }
        }

        private void handlePendingList() {
            while (true){
                try {
                    //1.获取pendingList中的异常订单信息 XREADGROUP GROUP g1 c1 COUNT 1   streams.order 0
                    List<MapRecord<String, Object, Object>> list = stringRedisTemplate.opsForStream().read(
                            Consumer.from("g1", "c1"),
                            StreamReadOptions.empty().count(1),
                            StreamOffset.create(queueName, ReadOffset.from("0"))
                    );
                    //2.判断消息获取是否成功
                    if(list == null || list.isEmpty()){
                        //如果获取失败，说明pendingList没有消息，继续下一次循环
                        break;
                    }
                    //3.解析消息中的订单信息
                    MapRecord<String, Object, Object> record = list.get(0);
                    Map<Object, Object> value = record.getValue();
                    VoucherOrder voucherOrder = BeanUtil.fillBeanWithMap(value, new VoucherOrder(), true);
                    //4.如果获取成功，可以下单
                    handleVoucherOrder(voucherOrder);
                    //5.ACK确认 SACK stream.orders g1 id
                    stringRedisTemplate.opsForStream().acknowledge(queueName,"g1",record.getId());
                } catch (Exception e) {
                    log.error("处理pendingList异常", e);
                    try {
                        Thread.sleep(500);
                    } catch (InterruptedException ex) {
                        throw new RuntimeException(ex);
                    }
                }
            }
        }
    }

//    private BlockingQueue<VoucherOrder> orderTasks = new ArrayBlockingQueue<>(1024 *1024);
//    private class VoucherOrderHandler implements Runnable {
//        public void run() {
//            while (true){
//                //获取订单信息
//                try {
//                    VoucherOrder order = orderTasks.take();
//                    //创建订单
//                    handleVoucherOrder(order);
//                } catch (InterruptedException e) {
//                    log.error("处理订单异常", e);
//                }
//            }
//        }
//    }

    private void handleVoucherOrder(VoucherOrder order) {
        Long userId = order.getUserId();
        //创建锁对象
        RLock lock = redissonClient.getLock("lock:order:" + userId);
        boolean isLock = lock.tryLock();
        if (!isLock) {
            //获取锁失败
            log.error("不允许重复下单");
            return ;
        } else {
            try {
                proxy.createVoucherOrder(order);
            } catch (IllegalStateException e) {
                throw new RuntimeException(e);
            } finally {
                lock.unlock();
            }
        }

    }
    private IVoucherOrderService proxy;

    @Override
    public Result seckillVoucher(Long voucherId) {
        Long userId = UserHolder.getUser().getId();
        Long orderId = redisIdWorker.nextId("order");
        // 1.执行lua脚本
        Long result = stringRedisTemplate.execute(
                SECKILL_SCRIPT,
                Collections.emptyList(),
                voucherId.toString(), userId.toString(), orderId.toString()
        );
        // 2.判断结果是否为0
        int res = result.intValue();
        if( res != 0){
            //2.1 不为0，没有购买资格
            return Result.fail(res == 1 ? "库存不足": "不能重复下单");
        }

        //获取代理对象
        //避免事务失效   通过代理来调用方法
        proxy = (IVoucherOrderService) AopContext.currentProxy();
        //3.返回订单id
        return Result.ok(orderId);
    }



//    @Override
//    public Result seckillVoucher(Long voucherId) {
//        Long userId = UserHolder.getUser().getId();
//        // 1.执行lua脚本
//        Long result = stringRedisTemplate.execute(
//                SECKILL_SCRIPT,
//                Collections.emptyList(),
//                voucherId.toString(), userId.toString()
//        );
//        // 2.判断结果是否为0
//        int res = result.intValue();
//        if( res != 0){
//            //2.1 不为0，没有购买资格
//            return Result.fail(res == 1 ? "库存不足": "不能重复下单");
//        }
//
//        //2.2 为0，有购买资格。把下单信息保存到阻塞队列
//        long orderId = redisIdWorker.nextId("order");
//
//        VoucherOrder voucherOrder = new VoucherOrder();
//        voucherOrder.setId(orderId);
//        voucherOrder.setUserId(userId);
//        voucherOrder.setVoucherId(voucherId);
//        // 放入阻塞队列
//        orderTasks.add(voucherOrder);
//        //获取代理对象
//        //避免事务失效   通过代理来调用方法
//        proxy = (IVoucherOrderService) AopContext.currentProxy();
//        //3.返回订单id
//        return Result.ok(orderId);
//    }

//    @Override
//    public Result seckillVoucher(Long voucherId) {
//        // 1.查询优惠券
//        SeckillVoucher voucher = seckillVoucherService.getById(voucherId);
//        // 2.判断秒杀是否开始
//        LocalDateTime beginTime = voucher.getBeginTime();
//        if (beginTime.isAfter(LocalDateTime.now())) {
//            return Result.fail("秒杀尚未开始");
//        }
//        // 3.判断秒杀是否结束
//        if (voucher.getEndTime().isBefore(LocalDateTime.now())) {
//            return Result.fail("秒杀已经结束");
//        }
//        // 4.判断库存是否充足
//        if (voucher.getStock() < 1) {
//            return Result.fail("库存不足");
//        }
//        //进行一人一单的判断
//        Long userId = UserHolder.getUser().getId();
//
//        //创建锁对象
//        RLock lock = redissonClient.getLock("lock:order:" + userId);
//        boolean isLock = lock.tryLock();
//        if (!isLock) {
//            //获取锁失败
//            return Result.fail("不允许重复下单");
//        } else {
//            try {
//                //避免事务失效   通过代理来调用方法
//                IVoucherOrderService proxy = (IVoucherOrderService) AopContext.currentProxy();
//                return proxy.createVoucherOrder(voucherId);
//            } catch (IllegalStateException e) {
//                throw new RuntimeException(e);
//            } finally {
//                lock.unlock();
//            }
//        }
//
//
////        SimpleRedisLock simpleRedisLock = new SimpleRedisLock("order:" + userId, stringRedisTemplate);
////        //获取锁
////        boolean isLock = simpleRedisLock.tryLock(1000L);
////        if (!isLock) {
////            //获取锁失败
////            return Result.fail("不允许重复下单");
////        } else {
////            try {
////                //避免事务失效   通过代理来调用方法
////                IVoucherOrderService proxy = (IVoucherOrderService) AopContext.currentProxy();
////                return proxy.createVoucherOrder(voucherId);
////            } catch (IllegalStateException e) {
////                throw new RuntimeException(e);
////            } finally {
////                simpleRedisLock.unlock();
////            }
////        }
//
//
////        //intern()确保只要是当前用户的id一样，那么在jvm中的对象就是同一个
////        synchronized (userId.toString().intern()) {
////            //避免事务失效   通过代理来调用方法
////            IVoucherOrderService proxy = (IVoucherOrderService) AopContext.currentProxy();
////            return proxy.createVoucherOrder(voucherId);
////        }
//    }

    @Transactional
    public void createVoucherOrder(VoucherOrder voucherOrder) {
        //进行一人一单的判断
        Long userId = voucherOrder.getUserId();
        int count = query().eq("user_id", userId).eq("voucher_id", voucherOrder.getVoucherId()).count();
        if (count > 0) {
            log.error("该用户已达到购买上限");
        }

        // 5.扣减库存
        boolean success = seckillVoucherService.update().setSql("stock = stock -1").eq("voucher_id", voucherOrder.getVoucherId()).gt("stock", 0).update();
        if (!success) {
            log.error("库存不足");
        }
        //创建订单
        save(voucherOrder);

    }
}
